Blood vessel occlusion auger

ABSTRACT

A blood occlusion auger having an in vivo distal auger tool coupled in operative association with an ex vivo auger control for opening and traversing occlusions in a blood vessel The auger control allows the selection of predetermined threshold forces and step-lengths values and operates in successive repetition of identical sequential stages, to traverse occlusions. Once disposed adjacent an occlusion, the auger tool, commanded by the auger control, operates in two states, first to radially dilate the vessel and second to penetrate distally into a furrow.

This application is a Divisional Application of U.S. application Ser.No. 11/602,106, filed Nov. 20, 2006, which application is a Continuationof PCT/IL2005/000607 filed Jun. 8, 2005, the priority date of which isclaimed herein, and the entire disclosures of both of which areincorporated herein by reference.

TECHNICAL FIELD

The present invention relates to devices and methods for restoring bloodflow in occluded blood vessels, and for traversing occlusions.

DEFINITIONS

Distal refers to both a direction of motion and a location,respectively, a movement in a direction away from an operator or alocation further from the operator, for example a portion of aninstrument located in vivo.Proximal refers to both a direction of motion and a location,respectively, a movement in a direction toward the operator or alocation nearer, to the operator, for example a portion of an instrumentlocated ex vivo.Axial indicates the direction substantially in the longitudinal axis ofa blood vessel.Lateral and radial refer to a direction substantially perpendicular tothe longitudinal axis of a blood vessel.A furrow is considered hereinbelow as being a substantially axial furrow340 in the vessel 300.

BACKGROUND ART

Partial occlusion of any artery or vein of the body, herein a vessel,may slow blood flow to the extent that affected tissue may receiveinadequate perfusion of life-giving oxygen, with sequelae of tissueischemia, ischemic pain and tissue necrosis. In the heart, timelyrestoration of blood flow through occluded cardiac vessels can avertcardiovascular attack (CVA), tissue scarring, cardiac malfunction and/ordeath.

A preferred treatment for restoring blood flow through a partiallyoccluded blood vessel uses a percutaneously-delivered wire having aspiraling wire jacket, herein a guide wire, whose leading end ispositioned distal to the occlusion. In angioplasty, for example, theguide wire is used to guide a balloon to the occlusion site where theballoon is expanded, thereby radially dilating the occlusion, andincreasing blood flow through the vessel.

In totally occluded blood vessels, including Chronic Total Occlusions(CTO's), the size of the occlusion and its hardness often make itimpossible for a guide wire to navigate through and distally past theocclusion. Restoring blood flow through a totally occluded vessel oftenrequires opening the chest and installing vessels that bypass theocclusion, a surgical procedure associated with high morbidity and riskof death.

Many tools exist for the treatment of occluded blood vessels, all havingtheir drawbacks.

In U.S. Pat. No. 6,599,304, Selmon et al., teach a device with “ . . .one or more hinged spreading or deflecting members that may bemechanically activated by an actuating member such as a pull wire ortube. A spreading or mechanical force may be thus applied to the bloodvessel wall and occlusion so as to tear, fracture or otherwise disrupt,the occlusion adjoining the vessel wall. This disruption of theocclusion may create a channel or a passageway of sufficient size forthe passage of a guidewire . . . ”. The deflecting members are divulgedas being jaws operated by an actuation element: “An actuation wire oractuation member 54 may be provided within the assembly to move the jawsections 42 from its first closed position to its second open position.In various embodiments, the jaw sections 42 may have a variety ofgeometries, including but not limited to, spade shaped, straight with aconcave curve at the end, straight with convex curve at the end,triangular (needle nose), rectangular and combinations thereof.”

In U.S. Pat. No. 6,579,302, Duerig et al. teach a device with a spreaderhaving a plurality of struts: “The spreader 15 may comprise a pluralityof longitudinally or circumferentially arranged struts extending betweenthe distal portion and the proximal portion of the spreader, such thatadvancing the spreader 15 over the core wire 20 frees the struts andallows them to expand to their largest diameter, and advancing the corewire 20 through the spreader 15 aligns the struts in a flat, closedposition.”

In U.S. Pat. No. 5,954,742, Osypka teach a device with an expanderforming a cylindrical cage: “As can be seen, for example, in FIGS. 6, 7and 8, the expander or dilator 5 forms an elongated at leastsubstantially cylindrical cage surrounded by straight elongated sections5 a′ of the expanding elements 5 a, and the sections 5 a′ are at leastsubstantially parallel to each other and to the central longitudinalaxis of the cage.”

In U.S. Pat. No. 5,741,270, Hansen et al., teach: “A pair of resilientconnecting members 202 are mounted onto the bracing member mounting pins208 and to the retracting member mounting pins 210. The connectingmembers 202 are made of thin strips of resilient material which regaintheir original shape after being deformed. One end of each of theconnecting members 202 is pivotally connected onto the bracing membermounting pins 208, whereas the other end of each of the connectingmembers 202 is pivotally connected to the retracting member mountingpins 210.”

In U.S. Pat. No. 4,648,402, Santos teaches a multilinkage mechanism:“Rear linkage 73 includes internal concave edge 773 and rear linkage 173includes internal concave edge 873 which accommodate sphere 78 when itis in its most anterior position when mechanism 70 is in the closedconfiguration. In the open configuration of mechanism 70, there is alsoa net rearward displacement of front linkages 74 and 174, and of movablefront section 76.”

In U.S. Pat. No. 4,848,342, Kaltenbach teaches a rotatable dilationcatheter with a spring coil: “The catheter includes a flexible wire orelongated member 1 which is provided with a swelling or head with aspherically curved surface 2 at its distal end. A spring coil 3 isslipped onto the wire 1 and this spring coil has opened turns which areradially expandable at its distal end to form a pressure member 4. Inthe illustrated embodiment, the coil 3 is a double coarse coil of steelwires, which adjacent a distal end of the wire 1 has an increasedspacing between the adjacent turns to form open turns. The diameter ofthe pressure member can be increased by axially compressing the openturns of the spring coil 3.”

In U.S. Pat. No. 6,800,085, Selmon et al., teach a catheter with ahousing: “The distal mounted housing may further include one or morehinged spreading or deflecting members that may be mechanicallyactivated by an actuating member such as a pull wire or tube.”Furthermore, there is an actuation device: “An actuation memberindicated by dotted lines 26 may move or actuate the blunt end memberfrom a first closed position, as illustrated in FIG. 1, to a second openposition, as illustrated in FIG. 2.”

In U.S. Pat. No. 6,638,247, Selmon et al., teach a device with: “Anactuation wire or actuation member 54 may be provided within theassembly to move the jaw sections 42 from its first closed position toits second open position. In various embodiments, the jaw sections 42may have a variety of geometries, including but not limited to, spadeshaped, straight with a concave curve at the end, straight with convexcurve at the end, triangular (needle nose), rectangular and combinationsthereof. The jaws 42 may be spaced apart or separated from one anothereven when closed as shown in FIG. 4.”

None of the above mentioned disclosures teach an in vivo device having abow, as a single asymmetric radially outward extensible flexible elementwith reduced radial dimensional configuration, and void of free radiallyextending extremities to prevent traumatic lesions to vessels, thatdilates an occluded blood vessel and permits to traverse an occlusion insuccessively repetitively predetermined controlled identical steps.Additionally, controlled flexion and extension of the bow, in controlledforce application and step-length, provide for a type self-propelleddevice that dilates an occluded blood vessel and permits to traverse anocclusion, without relying on the skills and dexterity of the operator.

DISCLOSURE OF THE INVENTION

An occlusion auger (100) is used for penetrating and traversing anocclusion (320) in a blood vessel (300) by performing a plurality ofrepeatable atraumatic single-sequence two-state consecutive actionsincluding first radial dilatation in one direction to crack open afurrow (340) in the occlusion, followed second by distal penetrationinto the furrow, and vice versa.

An occlusion auger (100) having an ex vivo auger control operates an invivo auger tool. Initially, the auger tool, trailing a shaft (130)containing a guide wire (120) is navigated adjacent the occlusion or ina furrow of the occlusion. In parallel or in sequence, predeterminedvalues are set at the auger control, namely dilatation threshold forcesand distal penetration step-length.

Next, the auger tool is operated under control of the predeterminedvalues, to sequentially repeat identical radial dilation and distalpenetration steps, without relying on the skills of the operator (OP).However, it is the task or the operator to conduct the auger toolsaxially into the vessel.

SUMMARY OF THE INVENTION

An aspect of some embodiments of the invention relates to a device foraugmenting a blood flow passage through a partially or fully occludedblood vessel, the device including an auger tool adapted for use in anin vivo blood vessel. A vessel occlusion auger, or occlusion auger,having an auger tool commanded by an ex vivo auger control, is definedas a device for use in an invasive surgical procedure to open a lumenthrough a partial or total occlusion disposed in a blood vessel.

The auger tool is configured to provide atraumatic engagement of in vivotissue, in rolling motion, under controlled force threshold andtranslation distance limits.

It is an object of the present invention to provide an occlusion auger(1000) and a method for implementing the occlusion auger, for distallytraversing an occlusion (320) in a vessel (300) having vessel walls(310). There is provided an auger tool (110) configured for atraumaticrepeatable operation in a sequence including both deflection to anarcuate state extending radially outward, and release to an expanded andstraightened state, and vice versa. The auger tool has an extrados whenarcuate, and also a tool tip (MT). In the arcuate state, when the augertool is disposed adjacent the occlusion, the tool tip and the extradosare embedded and releasably retained in, respectively, a tip depression(141) and an are depression (151) disposed opposite to each other inspaced-apart relationship in the vessel, whereby the vessel is dilatedasymmetrically in radial outward direction for opening a furrow (340) inthe occlusion.

Furthermore, in the expanded state, following the arcuate state, thetool tip translates into the furrow distally away from the arcdepression, by one step length for each one sequence of operation. Eachnext sequence of operation of the auger tool is accompanied by a nextdistal tip depression, and a next distal arc depression, and both thenext distal tip and the next arc depression are disposed distallyrelative to, respectively, a previous tip and a previous arc depression.

Moreover, the auger tool is configured for flexing in controlleddeflection curve shape. Also, by embedding the tool tip first andthereafter the extrados induces atraumatic rolling motion is providedfor radial outward dilation, and for distal translation.

It is another object of the present invention to provide an auger toolfor operation in a specific number of successive sequences, accompaniedby a same specific number or radial outward dilations and of distaltranslations. The auger tool translates substantially axially anddistally into the vessel in successive crawling motion imparted by eachsuccessive sequence of operation.

It is yet another object of the present invention to provide anocclusion auger having a shaft (130) with an ex vivo proximal end (134),an in vivo distal end (135), an exterior (136), and an interior (137)supporting therein a wire (120) having an ex vivo proximal extremity(125) and an in vivo distal extremity portion (121). The auger tool(100) has a flexible and resilient bow (110) disposed in distalcoextensive longitudinal alignment with the distal end of the shaft, andthe bow has a bow back (117) intermediate a bow root (115) fixedlyattached to and supported by the distal end of the shaft, and a face(112, 112T, 112OV) extending distally away from the bow back, the lacehaving a face bore (113, 113F, 113OV), which is configured for passagetherethrough of the wire. In addition, a force applicator (122, 122R,122M, 122OV) retained at the distal extremity of the wire, is configuredfor operative association with the face bore and with the shaft, to flexthe bow to the arcuate state when the shaft is translated distallyrelative to the force applicator, for the extrados to dilate the vesselin asymmetric radial outward direction, and to release the bow to theexpanded state when the wire is released, for the face to translate theforce applicator distally away relative to the arc depression by onepredetermined step length for each one sequence of operation.

The force applicator has at least one flexible portion, and at least oneresilient portion.

It is still another object of the present invention to provide a forceapplicator that is disposed in longitudinal coextensive distal alignmentwith the face, and where the bow is tangential to and longitudinallyaligned with the shaft, and is configured to taper from the bow rootdistally away, forming a single protrusion extending radially outwardrelative to the wire, whereby alignment of the force applicator with thebow, tapering of the bow, and the single radial protrusion enhancereduced dimensions.

It is yet still another object of the present invention to provide aforce applicator that is permanently attached to the distal extremity ofthe wire, and where the force applicator and the face bore areconfigured for either one of both, permitting passage of the forceapplicator through the face bore, and preventing passage of the forceapplicator through the face bore. In addition, the force applicator andthe face bore may be configured for both, permitting passage of theforce applicator through the face bore, and preventing passage of theforce applicator through the face bore. Likewise, the force applicatormay be retained to the face in proximally controlled attachment release.

It is a further object of the present invention to provide a bow that isconfigured with a distally gradually diminishing spring rate coefficientfor deflection under larger force at the bow root and under smallerforce at the face, whereby controlled atraumatic bow deflectioncurvature is achieved. Moreover, the bow is configured with a distallygradually diminishing spring rate coefficient for deflection underlarger force at the bow root and under less force at the face, and thearc depression of the extrados is larger than the tip depression.

It is yet a further object of the present invention to provide occlusionauger having an auger control (500) that is disposed ex vivo inoperative association with the auger tool, including a force limiterconfigured for adjustable selection and setting of a predeterminedthreshold limit of forces applied to the auger tool, and a step limiterconfigured for adjustable selection and setting of a predetermineddistal step length taken in each one sequence of operation.

It is yet still a further object of the present invention to provide anauger control that maintains identical predetermined forces limit andstep length settings for each sequence in a series of successivelyrepeated sequences. Furthermore, the auger tool includes

-   -   a shaft lock for releasably locking the shaft relative to the        auger control and for limiting force applied on the shaft, and a        stepper for distally translating the shaft in predetermined step        length,    -   a wire lock for releasably locking the wire relative to the        auger control and for limiting force applied on the wire, and    -   the auger control is configured for operative handling and        control of the wire and of the shaft both independently and in        combination.

It is an additional object of the present invention to provide anocclusion auger that when in the arcuate state has a bow back with anextrados extending radially outward and away from the wire, and the bowroot is retained to the shaft, and the face is retained to the wire bythe face bore, for continuous control of the deflection of the bow,whereby the force applicator is the sole free-extending extremity of theauger tool.

It is yet an additional object of the present invention to provide anocclusion tool that has at least one cutting edge (112C) disposed on aperimeter (112P) of the face to extend radially outward and away fromthe face bore, and where the at least one cutting edge is configured forradially cutting into occlusion tissue, in vivo

It is yet still an additional object of the present invention to providean occlusion tool where:

a. the force applicator is navigated to engage an axial furrow in anocclusion,

b. the face is abutted on the force applicator,

c. the auger tool is operated to the arcuate state, whereby kineticenergy is accumulated and the bow asymmetrically dilates the vessel intoone radial outward direction,

d. the auger tool is released to the expanded state, and the releasedkinetic energy extends the bow to translate the force applicatordistally into the furrow, and

e. the sequence of steps c. and d. are successively repeatable until theocclusion is traversed and augmented blood flow is restored.

It is one more additional object of the present invention to provide anocclusion tool where when in the arcuate state, the force applicatorreleasably embeds in a tip depression, the extrados embeds in an arcdepression to dilate the furrow, and initiate a crack propagationmechanism to open and distally deepen the furrow, and when in theexpanded state, the force applicator is received by one step lengthdistally deeper in the deepened furrow.

It is yet still another additional object of the present invention toprovide an occlusion tool where when in the arcuate state, the forceapplicator releasably embeds in a tip depression, the extrados embeds inan arc depression to dilate the furrow, and initiate a crack propagationmechanism to open and distally deepen the furrow, and when in theexpanded state, the force applicator is received by one step lengthdistally deeper in the deepened furrow

It is still a further object of the present invention to provide anocclusion auger wherein when the force applicator extends distally pastan occlusion, either one of both operations is performed:

the wire is navigated to engage a next occlusion and a next occlusiontraversing sequence is performed, and

-   -   the shaft is proximally retrieved ex vivo while the wire remains        disposed in place for use in a next treatment intervention

It is moreover a further object of the present invention to provide anocclusion auger wherein when the force applicator extends distally pasta traversed occlusion, the shaft is retrievable ex vivo, by either oneof both:

retrieving the face bore proximally away relative to the forceapplicator and sliding the face bore over the wire, and

disengaging the face distally away from the force applicator, andretrieving the shaft proximally.

It is furthermore an object of the present invention to provide anocclusion auger wherein the auger tool is configured to accommodatelocking, translation, and rotation of the shaft and of the wire ineither one of both mutually independent operation, and in mutuallyassociative operation.

It is furthermore still an object of the present invention to provide anocclusion auger wherein the arcuate state is achieved, by distaltranslation of the shaft relative to and over the wire until the faceabuts the force applicator, and the expanded state is achieved by distaltranslation of the wire relative to the shaft. The distal translationhas a step length that ranges from 1 mm to 50 mm.

It is yet still a further object of the present invention to provide anocclusion auger wherein the tip depression is disposed opposite the arcdepression, and the arc depression has a span selected from the group ofspans consisting of a span extending proximally and distally relative tothe tip depression, a span extending proximally relative to the tipdepression, and a span extending distally relative to the tipdepression.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting embodiments of the invention will be described withreference to the following description of exemplary embodiments, inconjunction with the figures. The figures are generally not shown toscale and any measurements are only meant to be exemplary and notnecessarily limiting. In the figures, identical structures, elements orparts which appear in more than one figure are preferably labeled with asame or similar number in all the figures in which they appear, inwhich:

FIG. 1 is a schematic block diagram of the occlusion auger,

FIG. 2 shows a side elevation of the distal in vivo portion of thevessel occlusion auger, according to FIG. 1,

FIG. 3 is a longitudinal cross-section of the side elevation shown inFIG. 2,

FIG. 4 shows an ex vivo auger actuator for the operation of the vesselocclusion auger,

FIG. 5 is a longitudinal cross-section of the auger actuator shown inFIG. 4,

FIG. 6 is an enlarged detail of the wire-locking mechanism of the augeractuator shown in FIG. 5,

FIG. 7 is an enlarged detail of the shaft locking mechanism of the augeractuator shown FIG. 5,

FIG. 8 shows a typical operating room used for a procedure with theocclusion auger according to FIG. 1,

FIGS. 9 and 10 show partial in vivo cross-sections of a procedure withthe occlusion auger according to FIG. 1,

FIGS. 11A, 11B, 12A to 12C, 13A, 13B, and 14A to 14C show details of thenavigation and the use of the occlusion auger of FIG. 1,

FIGS. 15A, 15B, 16A, 16B, 17A, 17B, and 18, show details of theoperation of the occlusion auger of FIG. 1,

FIGS. 19A and 19B shows enhancements of the occlusion auger of FIG. 1,

FIGS. 20A to 20D illustrate the mechanism of bending and expansion ofthe occlusion auger of FIG. 1.

FIGS. 21A to 21C depict various bow root configurations,

FIGS. 2A and 22B present optional embodiments of the face of the bow,

FIGS. 23A to 23C depict a further embodiment of the auger tool, and

FIGS. 24A, 24B, 25A to 25C, and 26 show details of various optionalembodiments for the force applicator and the face of the bow.

BEST MODES FOR CARRYING OUT THE INVENTION

FIG. 1 presents a block diagram showing the mutual relationship and themain elements of the occlusion auger 1000 when in operation, with aproximal ex vivo portion, and a distal in vivo portion, shown separatedby a dashed line S-S. A shaft 130 and a guide wire 120, or wire 120,both have a proximal ex vivo portion and a distal in vivo portion. Aguiding catheter wherethrough the in vivo portion of the occlusion auger1000 is introduced into the patient, and the patient, are not shown inFIG. 1.

An operator OP handles the occlusion auger 1000 via an ex vivo augeractuator 500, which controls an in vivo auger tool 100 operating adistal portion of the wire 120 and of the shaft 130. In the preferredembodiment 1000, the auger tool 100 has for example, a flexible andresilient element, such as a bow 110, fixedly coupled to the distalportion of the shaft 130, and removably engaging an in vivo forceapplicator 122 fixed to the in vivo distal extremity of the wire 120.

In operation, the wire 120 is first navigated distally via blood vessels300, inside vessel walls 310, until the force applicator 122 engages anocclusion 320, or a furrow 340 in an occlusion 320. Then, the shaft 130and the force applicator 122 are coupled and operated to flex andarcuate the bow 110. Thereby, the force applicator 122 and the extradosof the arcuate flexed bow back 117 are embeded in occlusion tissuelining the furrow 340, in releasable anchoring disposed adjacentopposite vessel walls 310.

In operation, flexing the bow 110 dilates the furrow 340 asymmetricallyinto one radial direction, providing forces to provoke and initiate acrack propagation mechanism in the occlusion 320, and to further openand distally deepen the furrow 340. Thereafter, forces on the bow 110are released whereby the elastic energy accumulated therein whileflexing is liberated to expand the bow 110, and to introduce the forceapplicator 122 by one step-length distally deeper into the furrow 340.

The flexure to arcuate and the release to expand the bow 110 arerespectively, a first and a second state of a sequence having twophases, controllably operated in successive repetition by the augeractuator 500 to cross the occlusion 320. If necessary, repetitiveoperation of a plurality of sequences is reiterated successively totraverse one or more occlusions. Figuratively, the auger tool 100coils-up when flexing, and uncoils when expanding, to progressesdistally in a worm-like type of crawling process.

The auger actuator 500 has a shaft locking mechanism 540, or shaft lock540, a step-length limiting mechanism 541, or stepper 541, and a forcelimiter 542, all coupled to the shaft 130. Furthermore, the augeractuator 500 has a wire locking mechanism 560, and a force limiter,other than the shaft force limiter, but also marked as 542 in FIG. 1,which are coupled to the wire 120. It is noted that the force applicator122 and the bow 110 return feedback control information to the forcelimiter 542.

There is also an optional release mechanism 125 to decouple the forceapplicator 122 in vivo from the bow 120, as further described in detailhereinbelow.

Vessel Auger Assembly

FIG. 2 shows a side elevation view of the in vivo auger tool 100, as anexemplary embodiment of a portion of the occlusion auger 1000, accordingto FIG. 1. The auger tool 100 includes a shaft 130, such as that of anavailable intravascular catheter system for the treatment of occludedblood vessels. The shaft 130 is distally terminated by, for example, abow 110 that is flexible and resilient, and has a distal end terminatedby a face 112 wherein a face bore 113 is opened. A guide wire 120, orwire 120, is disposed coaxially through the interior of the shaft 130and through the face bore 113, which is configured to allow controlledbi-directional translation and rotation of the wire 120. The wire 120has a flexible and resilient free distal extremity portion 121,terminated by a force applicator 122, shown as a bulb 122B, andaccommodated to variably and reversibly extend distally away from theface 112. In an exemplary embodiment, both the force applicator 122 andthe bow 110 include a radio opaque material so that an operator OPviewing an imaging system, for example a Computer Tomography (CT) or aRadiograph, may visualize the disposition of the force applicator 122with respect to the face 112.

As shown in FIG. 2, the distal extremity portion 121 of the wire 120,extending distally away from the lace 112, is bent to an angle α withrespect to the shaft 130. When the wire 120 is rotated inside the shaft130, then the distal extremity 121 becomes a directrix that describesthe mantle of a cone. Therefore, when the wire 120 is disposed in theinterior of a vessel 300, and the operator OP desires to introduce thedistal extremity portion 121 past a curve or into a branch of a vessel300, the wire 120 is rotated until the distal extremity portion 121points into the direction appropriate to proceed past the curve or intothe branch.

FIGS. 2 and 3 also indicate details of the shaft 130, such as theproximal end, the in vivo distal end, the exterior, and the interior,which supports a wire therein. Also shown are the ex vivo proximalextremity portion and the in vivo distal extremity portion, of the wire120.

FIG. 3 is a longitudinal cross-section of FIG. 2, where the bulb 122B isshown retracted proximally and in abutment with the face 112, incontrast with the position depicted in FIG. 2, where the bulb 122B isshown in distal extension away from the face 112.

A relief 114, which locally decreases the cross-sectional area of thebow 110 defines a specific location about which the bow 110 will flexand bend when urged to arcuate. The shape of the relief 114 isirrelevant as long as the functional requirements are met, and may beimplemented as a cutout formed by plane sections, or as a rounded-offcurve of a selected shape. The shape of the relief 114 is thus notlimited to any specific configuration and may be selected as desired.

The portion of the bow 110 extending from the proximal extremity thereofto the relief 114 forms a bow root 115, and the portion of the bow 110extending from the relief 114 to the face 112 forms a bow back 117. Thebow root 115 and a proximal portion of the bow back 117 are disposed ina cutout 132 entered in the distal portion of the shaft 130, so that thebow 110 longitudinally extends in co-alignment with the shaft 130. Thebow 110 is made for example, from a super-flexible and resilientmaterial, such as nitinol, and is exemplarily, about 1.4 centimeterslong.

To reduce dimensions, the force applicator 122 is disposed inlongitudinal coextensive distal alignment with the face 112, and the bow110 is configured to taper from the bow root 115 distally away, to forma single protrusion extending radially outward relative to the wire 120.Thereby, due to the alignment of the force applicator 122 with the face112, the tapering of the bow 110, and the single radial protrusion,reduced dimensions are enhanced.

Although not shown in the Figs., the bow 110 tapers distally away, thushaying a larger cross-sectional area proximally than distally. Actuallythe bow 110 is one possible implementation of a portion of the augertool 100. The bow 110 is a flexible and resilient beam cantilevered tothe shaft 130 with the face 112 as the beam free end. The bow back 117is actually a flat spring for which the distal taper provides a lowerspring rate or spring coefficient at the distal extremity, here the face112, than at the proximal cantilevered extremity, here the relief 114.The importance of the bow 110 being “softer” distally, and “harder”proximally is detailed hereinbelow.

In an exemplary embodiment, the bow root 115 and at least a proximalportion of the relief 114, are belted by a surrounding shrink tube 116.The shrink tube 116 is shrunk to fixedly retain the bow 110 inco-alignment to the shall 130, and to prevent any relative motionbetween the bow 110 and the shaft 130. The shrink tube 116 also gripsthe relief 114 to better anchor the bow 110 onto the shall 130. The bowback 117 is not covered by the shrink tube 116, and is thus free toflex.

The fixed retention of the bow root 115 to the shaft 130 is possiblyachieved with any practical means available, and is not restricted tothe use of a shrink tube 116, as further described hereinbelow. Ifdesired, the shrink tube 116 is selected from materials that can beinduced to form a strong attachment to the bow 110, for example,materials including Nylon 11™ or Nylon 6™. It is remarked that the shaft130 may have a diameter of 0.55 mm for example.

FIG. 3 illustrates a coiled spiraling wire jacket 124 encasing thedistal extremity portion 121 of the wire 120. The wire jacket 124 isabout 20 cm long and remains conformal to the wire 120 that tapersdistally along that same length, from, say a diameter of 0.05 mm, downto 0.01 mm. In an exemplary embodiment, the face bore 113 has a diameterof 0.3 mm and the bulb 112B is 0.35 mm in diameter.

FIG. 3 also depicts that the distal portion of the wire 120 includes acore wire 126 encased in the spiraling wire jacket 124. In an exemplaryembodiment, the wire jacket 124 is 1 to 0.5 millimeters in diameter andthe core wire 126 has a diameter ranging from 0.05 mm to 0.01 mm. Forthe sake of clarity, reference is made hereinbelow simply to “wire 120”.

Although the auger tool 100 was described as having a bow 110, otherimplementations are possible, as long as the functional and atraumaticrequirements are respected. This means that it is always necessary toassure controlled tension and flexure forces, to control radial outwardextension in the arcuate state, as well as distal translation when inreturn to the expanded state.

FIG. 4 presents the ex vivo auger actuator 500 for the operation of thein vivo auger tool 100, and FIG. 5 is a longitudinal cross-section ofFIG. 4.

Referring to FIGS. 4 and 5, the auger actuator 500 includes a distalshaft control 501 supported concentrically in proximal co-alignedextension by a substantially cylindrical wire handle 550. A common axialconduit 510 pierces both the distal shaft control 501 and the wirehandle 550. A distal portion 503 of the conduit 510 passing throughoutthe distal shaft control 501 is configured to accommodate free passagetherethrough of the shaft 130, whereas a proximal portion 553 of conduit510 passing throughout the wire handle 550 is configured to accommodatefree passage therethrough of the wire 120. The shaft 130, which isdisposed in the wider portion 503, cannot penetrate into the narrowerproximal portion 553 of the conduit 510 passing through the wire handle550.

The shaft control 501 is of unitary construction and includes ashaft-nose 530, a collar 532, and a shaft body 534, all of generallycylindrical shape and disposed in concentric coextensive alignment. Theshaft-nose 530 is oriented in the distal direction, proximally followedfirst by the collar 532 and second, by the shaft body 534. The collar532 protrudes radially outward and away from the external surface of theshaft-nose 530, the shaft body 534, and the wire handle 550. A wirelocking mechanism 560, or wire lock 560, is proximally and coaxiallyappended to the wire handle 550.

FIG. 5 further depicts a step limiter 541, or stepper 541, for setting astep length, for example by help of a setscrew 543 coupled to the wirehandle 550, where the setscrew 543 is received in a relief 545 cut inthe shaft body 534, operating as described hereinbelow.

The shaft body 534 is configured as a male cylinder coaxially receivedin the interior of an axial female bore entered into the wire handle550, and is configured to permit mutual relative displacement inbi-directional translation and in bi-directional rotation, between boththe shaft control 501 and the wire handle 550. Relative to the wirehandle 550, the collar 532 is displaceable in bi-directional rotationand in translation distally outward and away therefrom, and proximallyback therein. The auger actuator assembly 500 is designed to permitprecise control of the bi-directional displacement in translation and inrotation of both the wire 120 and of the shaft 130, as described indetail hereinbelow.

FIG. 6 is an enlarged detail of the wire-locking mechanism 560, having aconfiguration well known to the art, and permitting to reversibly lockthe guide wire 120 relative to the wire handle 550, when desired. Athreaded extension 562 carrying an external male screwthread is disposedconcentrically and in proximal coextension to the proximal extremity ofthe wire handle 550 for matching engagement with a female screwthreaddisposed on the interior of a cap nut 564. The proximal portion 553 ofthe common axial conduit 510 coaxially pierces both the threadedextension 562 and the cap nut 564.

A wire glans 566, having an axial bore for the passage of the wire 120therethrough, has a wire stem 568 and wire locking jaws 570. The wirestern 568 and the wire locking jaws 570 are received in an appropriatewidening entered in the proximal extremity 553 of the axial conduit 510.The wire locking jaws 570 of the glans 566 resiliently separate into aplurality of flexible and resilient jaws configured to operate as acone-locking mechanism. Further details for this well-known cone-lockingmechanism are superfluous.

It is understood that when the female cap nut 564 is threadingly engagedon the male screw-threaded tail 562, the cap nut 564 applies compressionforces on the wire locking jaws 570 that deflect to firmly lock onto thewire 120 and prevent displacement thereof relative to the wire handle550. It is also clear that when the female cap nut 564 is threadinglydisengaged from the male threaded tail 562, the wire locking jaws 570resiliently release their grip on the wire 120, which then becomes ableto freely translate and rotate relative to the wire handle 550.

When the wire locking mechanism 560 is locked onto the wire 120, and thewire handle 550 is rotated clockwise and anticlockwise, then the wire120 will rotate in the same direction, respectively, clockwise andanticlockwise. Likewise, the wire 120 can now be translatedlongitudinally distally or proximally to, respectively, extend distallyout, as shown in FIG. 2, or to retract proximally.

In an exemplary embodiment, the wire locking jaws 570 are made from amaterial including for example, metal, such as brass, or a polymericplastic material known by the trade name Acculon™.

The wire locking mechanism 560 has a built-in force limiting mechanism.The force applied by the wire locking jaws 570 on the wire 120 definethe load under which the wire will slip out of the wire locking jaws570. Thus the more and the harder the cap nut 564 is screw threaded onthe male threaded tail 562, the higher the retention force on the wire120, and vice versa. Other force limiting mechanisms are alsoapplicable. Indication of the retaining force threshold of the wire 120may also be provided.

As described hereinbelow, translation, rotation, and standstill of thewire 120 and of the shalt 130 are mutually independent, but may beoperated in cooperative association.

FIG. 7 shows a longitudinal axial cross-section of a shaft lockingmechanism 540 disposed in the distal portion of the shaft control 501 inwhich a plurality of shaft locking jaws 528 releasably lock onto theshaft 130, thereby preventing longitudinal and rotational displacementof the shaft 130 relative to the shaft control 501.

In an exemplary embodiment, the shaft nose 530 is accommodated with aconcentric nose opening 535 for receiving therein a shaft stem 531 of ashaft glans 533 having a plurality of flexible and resilient shaftlocking jaws 528. The shaft locking jaws 528, concentrically pierced bythe distal portion 503 of the axial conduit 510, operate to releasablylock onto the shaft 130 by a cone-locking mechanism configuration wellknown to the art.

The shaft glans 533 is fixedly coupled in axial co-aligned dispositionto a slider 524 accommodated to freely translate axially andlongitudinally, thus both distally and proximally, in the interior of achamber 536. The chamber 536 is a hollowed out volume disposed in theinterior of the shaft nose 530. A resilient element 522, such as one ormore helical coil spring(s) 522, appropriately housed in a blind springbore 538 opened in parallel to the conduit 510 into the shaft nose 530,are accommodated to receive the spring(s) 522. The resilient element 522biases the slider 524 proximally away. Thereby, the slider 524 retractsthe shaft glans 533 into the shaft nose 530, whereby the shaft lockingjaws 528 lock onto the shaft 130, preventing translation and rotationthereof relative to the shaft control 501.

When the shaft locking mechanism 540 is locked onto the shaft 130, andthe collar 532 is translated distally and proximately, or rotated, thenthe shaft 130 also, respectively, translates distally and proximately,or rotates, relative to the wire handle 550, shown in FIG. 5.

To release the locked shaft 130, the slider 524 is translated distally,whereby the shaft locking jaws 528 are pushed distally out of the noseopening 535, and flex radially out and away. Thereby, the resilientshaft locking jaws 528 open to release grip and release the shaft 130 tofreely translate and rotate. To this end, a plunger 520, retained inpivotal freedom of motion to the shaft control 501, is provided with awedge 521 configured to engage a matching groove 523 accommodated forthis purpose in the slider 524. When the operator OP depresses theplunger 520, then the wedge 521 pivots to engage the groove 523. Therebythe slider 524 is driven distally against the resilient element 522, torelease the lock of the resilient shaft locking jaws 528 on the shaft130.

When the shaft-locking mechanism 540 is released by depression of theplunger 520, the shaft 130 is free to translate and rotate. It is alsounderstood that the purpose of translation and rotation or the guidewire 120 and of the shaft 130 is to allow an operator OP to preciselyoperate and position the auger tool 100 with respect to an occlusion 320disposed in a vessel 300. Moreover, the plunger 520 operates as anemergency button, permitting to immediately disconnect the shaft and torelieve the vessel 300 from any force or moment applied thereon by theauger tool 100.

The shaft-locking mechanism 540 has a built-in force limiting mechanism,permitting to select a threshold limit to prevent the exertion ofexcessive forces on the force applicator 122, and on the bow 110. Thebias exerted by the resilient element 522 on the slider 524 is the forceby which the shaft glans 533 is pulled proximally, and the more springbias, the more forceful the proximal pull. The proximal pull of theslider 524 is applied to the shaft glans 533 to lock the shaft 130 witha force proportional to the bias applied by the resilient element 522.One shaft retaining force control mechanism consists of replacing aninstalled resilient element 522 by a harder or softer one, to obtain,respectively, higher or lower shaft retention locking forces.

Other shaft-locking force control mechanisms are possible. One example,not shown in the Figs., is the preloading of a spring 522, say byoperating a controllable screw for the releasable axial compression ofthe spring. The more the spring 522 is compressed, the better the shaftlocking jaws 528 clamp the shaft 130, and the higher the lock retentionforces on the shaft 130.

Hence, when the bow 110 is flexed to arcuate, a force of magnitude lowerthan a limit threshold will prevent breakage of the guide wire 120 andseparation of the force applicator 122 therefrom. In addition, theradial force of the bow 110 against a vessel wall 310 may be kept belowa threshold limit, to prevent damage to a vessel 300.

In an exemplary embodiment, the shaft locking jaws 528 are made from anelastomeric material including, for example, a polymeric plasticmaterial known by the trade name Teflon™. Given the relatively lowcoefficient of friction of the selected material, the shaft-lockingmechanism 540 will give way above a determined force, to allow the shaft130 to slip on the shaft locking jaws 528, and prevent the applicationof a higher than desired force on the wire 120, on the force applicator122, and on the bow 110.

FIG. 5 depicts a conceptual embodiment of the step-length limiter 541,also indicated in FIG. 1. The setscrew 543, coupled to the wire handle550, and so extending radially inward to be received in the relief 545,operates as a stopper to limit the step-length. When the shaft body 534is translated distally, the translation will stop when the setscrew 543abuts the proximal wall 547 of the relief 545. Assuming that the shaftlock 540 is locked on the shaft 130, and the wire lock 560 is locked onthe wire 120, then when the shaft body 534 is translated distally,stopping of the translation of the setscrew 543 on the proximal wall 547will limit the distal translation step-length imparted to the shaft 130relative to the wire 120.

The step-length limiter 541 is possibly implemented in various versions,not described herein. For example, the setscrew 543, or any othermechanical stopper such as a pin, may be disposed in adjustable settingon the wire handle 550 relative to the proximal wall 547, to provide foran adjustable step-length. Although not shown in the Figs., one may alsoconsider piercing bores into the wire handle 550, at various distancesfrom the proximal wall 547, to achieves various step lengths when thesetscrew 543, or a pin, are entered into an appropriately selected bore.Evidently, other implementations of the step-length limiter 541 arepossible.

The operator OP is thus presented with a multi functional auger control500, having a shaft lock 540 for releasably locking the shaft 130relative to the auger control 500 and for limiting force applied on theshaft 130, a stepper 541 for distally translating the shaft 130 inpredetermined step length, a wire lock 560 for releasably locking thewire 120 relative to the auger control 500 and for limiting forceapplied on the wire. It is noted that the auger control 500 isconfigured for operative handling and control of the wire 120 and of theshaft 130 both independently and in combination. In addition, it isnoted that the shaft 130 may be retrieved distally out of the augercontrol 500, and that the wire 120 may be retrieved out of the augercontrol 500 both distally and proximally.

The auger control 500 is thus disposed ex vivo in operative associationwith the auger tool 100, including an inherent force limiting mechanismconfigured for the adjustable selection and for the setting of apredetermined threshold limit of shaft forces and of wire forces appliedto the auger tool 100, and a step limiter configured for the adjustableselection and for setting of a predetermined distal step lengthidentically taken and repeated in each one sequence of operation. It isnot the operator OP but the auger control that maintains identicalpredetermined forces limit and step length settings for each sequence ina series of successively repeated sequences.

Treating an Occluded Vessel

FIG. 8 shows a typical operating room 400 used for a procedure with theocclusion auger 1000 that includes a surgical table 458, an imager 468and an imaging display 470 that provides a real-time image of a treatedvessel 300. In an exemplary embodiment, wherein the coronary artery 300is being treated, a patient 420 is placed in the prone position on thetable 458 and the shaft 130 is passed through a catheter 430 that entersthe patient 420 through an incision 424 into a femoral artery 428, asillustrated in FIG. 9.

FIG. 9 and FIG. 10, which is an enlarged detail of FIG. 9, show apartial in vivo cross-section of the guiding catheter 430 enteringthrough an incision 424 into the femoral artery 428, seen in cutaway.The auger actuator assembly 500 is manipulated so that the shaft 130passes through the guiding catheter 430 toward a heart 482, where acatheter distal end 431 communicates with a coronary artery 490 having avessel branch 300 that contains an occlusion 320.

To treat an occlusion 320, it is first necessary to navigate the distalportion of the occlusion auger 1000 via vessels 300 until the auger tool100 meets the occlusion 320. The auger tool 100 is operated with theforce applicator 122 being extended distally away from the face 112, asseen in vivo in FIG. 10. The distal wire extremity portion 121,terminated by the tool tip MT, hangs free in a flexible configuration,allowing the wire 120 to flex and curve through bends and branchesencountered in blood vessels.

In practice, the occlusion auger 1000 is supplied with a wire 120 thatis about 185 cm long, and a shaft 110 having a length of some 140 cm. Byfactory setting, the force applicator 122 extends some 45 cm distallyaway from the face 112. That distance generally suits the operator.Extension pieces, not shown in the Figs. but used in common practice,may be attached to both the wire 120 and the shaft 130, if desired.

It is always possible to alter this factory-set disposition. To extendthe bulb 122 distally away from the face 112, the auger occlusionassembly 500 has to be manipulated as follows. The shaft lockingmechanism 540 is locked while the wire locking mechanism 560 is releasedand the guide wire 120 is manually pushed distally relative to the wirehandle 550, to extend say for some 40 to 100 mm. To maintain a selecteddistance between the force applicator 122 and the face 112, the wirelocking mechanism 560 is locked, as is the shaft locking mechanism 540,so that translation of the auger tool 500 will simultaneously translateboth the wire 120 and the shaft 130.

In a first step, as shown in vivo in FIG. 11A, the operator navigatessimultaneously both the shall 130, not shown in FIG. 11A, and the wire120, or only the wire 120, distally into the vessel 300, in manualtranslation toward and until the tool tip MT, here the force applicator122, contacts the occlusion 320 as distally as possible, into the furrow340.

In a second step, the shaft locking mechanism 540 is locked, and thewire locking mechanism 560 is unlocked. The guide wire 120 is kept inplace by being firmly retained in one hand by the operator OP, say inthe left hand LH, while the other hand pushes the auger actuator 500,thus also the shaft 130, in distal translation over the wire 120, asshown ex vivo in FIG. 11B. It is noted that the shaft locking mechanism540 is locked since the plunger 520 is not depressed. The distaltranslation terminates when the face 112 comes to rest in abutment withthe force applicator 122, as shown in vivo in FIG. 12A.

It is noted that when the face 112 abuts the force applicator 122, thebow 110 increases the rigidity of the distal extremity portion 121 ofthe guide wire 120, which is thereby stiffened. In addition, a visualfeedback signal is provided ex vivo to the operator OP, to indicate thatthe bulb 122 is in mechanical contact with the face 112, by uncovering amark, not shown in the Figs., disposed on the wire 120. A mark, sign, orindicia, is appropriately disposed on a proximal portion of the wire120, so that when the shaft is introduced distally to have the face 112abut the bulb 122, the mark is uncovered ex vivo when contact is made,by appearing proximally out of the auger actuator assembly 500.

By use of common practice radio opaque material, the disposition and therelative location of the various components of the auger tool 100 arealso presented to the operator on an X-ray device.

To orient the face 112 in an appropriately selected direction forfurther engagement as deep as possible into the furrow 340 of anocclusion 320, the shaft locking mechanism 540 and the wire lockingmechanism 560 are first locked. Next, the auger actuator 500 is held byhand, as shown ex vivo in FIG. 12B, and the collar 532 is rotated in thedesired direction, say by the thumb T, to rotate the shaft 130 togetherwith the bow 110 and the face 112. With both the wire locking mechanism560 and the shaft lock mechanism 540 locked, it is possible to rotatethe collar 532 in either direction and to translate the shaft 130distally, as shown ex vivo in FIG. 12B by, respectively, the arrows Aand R.

Evidently, it is also possible to unlock the wire locking mechanism 560,to extend the force applicator 122 distally away from the face 112, andto handle the guide wire 120 independently, even though the formerconfiguration is more rigid than the latter.

The auger tool 100 is now well positioned to threat an occlusion 320,either if penetration of the force applicator 122 into the furrow 340was successful, as by FIG. 12C, or even when the force applicator 122only abuts on the occlusion 320, as by FIG. 12A.

In a third step, as seen in ex vivo in FIG. 13A, with the forceapplicator 122 abutting on the face 112, and with both the shaft and thewire locking mechanisms, respectively 540 and 560 being locked, thecollar 532 is pushed distally away from the wire handle 550, which isfirmly retained, in the palm of the hand H by the fingers F of anoperator OP. The collar 532 is pushed with the thumb T to translatedistally, in a direction indicated by the arrow A, causing the shaft 130to translate distally relative to the wire 120, through an axialdistance D, for example, of 0.5 centimeters.

Transition from the expanded state following the arcuate state causesthe tool tip MT to translate into the furrow 340 distally away from thearc depression, by one step length for each one sequence of operation.In the same manner, each next sequence of operation of the auger tool isaccompanied by a next distal tip depression, and a next distal arcdepression, and both the next distal tip and the next arc depression aredisposed distally relative to, respectively, a previous tip and aprevious arc depression. When the auger tool 100 is operated in aspecific number of successive sequences, a same specific number ofradial outward dilations and of distal translations accompanies thesesequences.

Since the wire 120 remains locked in place while the shaft 130 is forcedto translate distally, and the force applicator 122 remains in abutmentagainst face 112, the resilient bow 110 is compelled to arcuate radiallyoutward and away with respect to the guide wire 120, as shown in FIG.13B. It is remarked that, as shown in FIG. 3, the face 112 is bent inoblique relative to the bow back 117, whereby the force applicator 122first contacts the face 112 at a well predetermined point P, shown inFIG. 3, where initial bending moments are applied. Furthermore, relief114 defines the location where the bow 110 will begin to flex, andarcuate.

As described hereinabove, the dimensions and the tapering of theflexible bow 110 are selected to ensure controlled predeterminedcurvature shapes for the radially outward bending of the bow 110 into areadily predictable mode of accurately defined deflection curvatures.

Referring to FIG. 13B and in other words, the tierce applicator 122embeds into one portion of the occlusion 320, creating a first tipdepression 141, into which the force applicator 122 anchors. With theforce applicator 122 anchored into the first tip depression 141, theextrados of the flexed bow back 117 of the arcuate bow 110 engages andembeds into a diametrically opposite lateral portion of the occlusion320, creating a first arc depression 151. The vessel 300 is therebydilated asymmetrically and radially outward, and the furrow 340 willcrack open, in a type of crack propagation process, successively openingdistally into newly opened furrow portions. In fact, the bending bow 110applies forces to expand the occlusion material and open a passage alonga true lumen, which is the last blood flow path that was availablebefore occlusion occurred.

It may thus be said that the tool tip MT of the auger tool 110 and theextrados of the bow back 117 are embedded and releasably retained in,respectively, the tip depression 141 and the arc depression 151 that aredisposed opposite to each other so in spaced-apart relationship in thevessel 300. Thereby the vessel is dilated asymmetrically in radialoutward direction for opening a furrow 340 in the occlusion 320.

To further penetrate into the occlusion 320, the force applicator 122has to progress distally to engage into and penetrate the newly openedfurrow portion 340. To this end, as shown ex vivo in FIG. 14A, thecollar 532 previously pushed through a distance D shown in FIG. 13A, isnow gripped between the thumb T and the index IND. Then, the otherfingers F are opened to release the grip of the palm of the hand H onthe wire handle 550, as shown ex vivo in FIG. 14B. Thereby, the energygathered in the arcuate bow 110 is released to push the face 112distally, in the direction indicated by the arrow AR, until the wirehandle 550 abuts on the collar 532.

The release of the energy-loaded bow 110 from the arcuate state to theextended state drives the face 112, and also the force applicator 122,distally into the furrow 340. When the flexed bow 110 is released, thefirst arc depression 151, into which the arcuate extrados of the bowback 117 is embedded, becomes a point of support wherefrom the face 112uncoils distally. Therefore, with the first arc depression as support,the shape of the curvature of the flexed bow 110 is different from thatof any shape developed during the bending of the bow 110.

While the distal portion of the bow 110, extending between the first arcdepression 151 and the tip depression 141 is released to straighten out,the proximal support of the extrados gradually regresses proximallyuntil return to the relief 114, which is reached in the expanded secondstate. This permits the force applicator 122 of the guide wire 120 topenetrate distally further into the furrow 340, as shown in vivo in FIG.14C.

As stated hereinabove, the distal portion of the wire 120 that retainsthe force applicator 122, and the bow 110 that is disposed on the distalportion of the shaft 130, form the auger tool 100. The auger tool 100 istensioned when the bow 110 is flexed to arcuate, by closing the distanceseparating the distal extremity of the shaft 130 from the face 112. Whenthe bow 110 is released to expand and straighten out, the forceapplicator 122 is pushed distally further into the furrow 340.

Usually, a single two-step sequence of operation of the auger tool 100is not sufficient to traverse and occlusion 320, and the sequence ofcoiling and uncoiling in worm-like crawling process must be repeated.

Once again, the collar 532 is pushed with the thumb T to translatedistally, in the same manner as describe in relation to FIGS. 12B and13A. In the bending phase of the crawling process, the bow 110 isarcuate, as shown in vivo in FIG. 15A, for the force applicator 122 tobecome engaged and anchored into a second tip depression 142, disposeddistally away from the first tip depression 141. Likewise, the bow back117 becomes engaged and anchored into a second arc depression 152,disposed distally away from the first arc depression 151, in a lateralportion of the occlusion 320, diametrically opposite to the second tipdepression 142.

Finally, the collar 532 is gripped by the thumb T and the index IND,while the fingers F are released, in the same manner as describedhereinabove in relation to FIGS. 14A and 14B. Thereby, the bow 110expands and straightens out, distally past the second tip depression142, and the bulb 122 is pushed to penetrate distally into the furrow340, in the second step of the crawling process, as shown in vivo inFIG. 15B.

Once more, the force applicator 122 engages a newly formed crack openedby asymmetric radial dilatation of the vessel 300. The crawling processof the auger tool 100, as described hereinabove, may be repeated asoften as needed to further penetrate into the occlusion 320, andfinally, to traverse and exit distally out of that occlusion.

It is not necessary to describe in details that the auger tool 100 maybe operated to traverse through a succession of occlusions disposed inthe vessel 300, until the guide wire traverses and emerges distally awayof the successive last occlusion. Typically, the bulb 122 progressesdistally in successive steps of some 5 millimeters, prior to creatingfurther tip and arc depressions.

During tests of the occlusion auger 1000, a flow passage through a7-centimeter long occlusion 320, has been opened following 14 sequencesof arcuate bending and expansion of the bow 110. In this manner, theocclusion auger 1000 may traverse a partial or a complete occlusion 320of virtually any length, including a hard Chronic Total Occlusion.

It is remarked that the two-step sequence of flexing and expanding ofthe bow 110 is governed and controlled by the ex vivo auger actuator500. This means that once the operator OP has selected and set valuesfor a step-length, a shaft retention force limit, and a wire retentionforce limit, these selected values are maintained and will be repeatedlyand identically applied in further successive sequences of operation,and will not rely on the skill and dexterity of the operator OP. Forexample, the operator OP may select and set the step-length distance outof a range of say 1 mm to 20 mm, and the selected distance D ismaintained throughout the consecutive sequences of operation performedby the auger tool 100, until set anew by the operator OP.

To help the operator OP using the occlusion auger 1000 to navigate andorient the force applicator 112 distally away, a radio-opaque dye 160may be injected into the vessel 300. The interior of the vessel 300thereby appears as a dark black area on the screen of an imaging system,clearly delimiting the borders of the vessel 300 and any occlusion 320.Thereby, tip depressions, lateral arc depressions, and cracks in afurrow 340 are well delimited. To further enhance the image presented tothe practitioner, an image of the auger tool 100 taken prior to theinjection of the dye 160 may be superimposed in contrast to the blackdyed image, to define the disposition of the auger tool 100 relative tothe occlusion 320.

FIG. 16A illustrates an example of the use of radio-opaque dye 160 priorto taking a bend 161 in an occlusion 320. As delimited by the dye 160,the detected furrow 340 offers a narrow bent lumen extending distallyaway ahead of the bulb 122. The operator will respond to such a vesselconfiguration by trying to navigate the wire 120 accordingly, and insertthe force applicator 122 as distally away as possible.

To this end, the wire locking mechanism 560 is released while theshaft-locking mechanism 540 remains locked, and the wire 120 is manuallytranslated distally, and rotated if necessary, until the wire 120penetrates the furrow 340 as distally as possible, as shown in vivo inFIG. 16B. The accompanying manipulation of the auger control assembly500 was described hereinabove, and is not repeated.

To traverse through a further distally disposed occlusion 320, the augertool 100 has to be operated again in a sequence of two-phased crawlingprocess steps. FIG. 17A depicts in vivo the arcuate bending of the bow110, creating the asymmetric radial dilatation, and FIG. 17B presentsthe longitudinal straightening out and expanded bow 110, where the forceapplicator 122 is shown distally away through and past the occlusion320. The auger tool 100 has thus embedded one more tip depression 145and one more arc depression 155. Further successive crawling steps, inaddition to the single step described hereinabove may be required topierce past a more massive and longer occlusion 320.

The occlusion auger 1000 may serve as a guide for additional surgicalinstruments used in simultaneous and/or following procedures. Forexample, the wire 120 may be disposed distally away from the occlusion320, as shown in FIG. 18, whereafter the shaft 130 is retrievedproximally away, for the wire 120 to serve as a guide to an angioplastycatheter supporting, as desired, a balloon with or without a stent.

To dispose the force applicator 122 and the wire 120 distally outwardand away from the occlusion 320, the wire-locking mechanism 560 isunlocked while the shaft-locking mechanism 540 remains locked. Then, theguide wire 120 if pushed distally into the interior of the vessel 300,well distally past the occlusion 320, a shown in vivo in FIG. 18.

Then, the auger tool 100 is retrieved ex vivo in proximal translationover the shaft 130. For this purpose, the proximal portion of the guidewire 120 is held stationary in one hand, while the other hand retrievesthe auger actuator 500, and therewith also the shaft 130, by proximaltranslation of the face bore 113 over the shaft 130. This is achievedafter the wire-locking mechanism 560 is unlocked and the shaft-lockingmechanism 540 is locked.

In an alternative procedure to distally remove the shall 130 ex vivo,the operator may choose to unlock both the shaft-locking mechanism 540and the wire-locking mechanism 560, and then remove the auger actuator500 in proximal translation over the shaft 130 and the wire 120, afterwhich, the shaft 130 is translated proximally with respect to the wire120, which remains in place.

Enhancements

During operation of the occlusion auger 1000, it is possible to preventproximal blood flow by use of an angioplasty catheter 180 with a balloon181, disposed around the shaft 130, as shown in FIG. 19A. If desired,the inflation of the balloon may be applied to symmetrically dilate thevessel 300 and to enhance the opening of a distal crack in the furrow340. Optionally, the angioplasty catheter 180 supports a stem, for useafter operation.

Since it is possible to insert additional treatment tools in vivo overthe shaft 130 and over the auger tool 100, it becomes superfluous toproximally retrieve the shaft 130 ex vivo after completion of theprocedure using the occlusion auger 1000. Therefore, after use of theocclusion auger 1000, the auger tool is left in place in vivo, and anadditional treatment tool is translated in vivo, over the auger tool,and disposed for further in vivo treatment.

In case of an acute occlusion, the bow 110 may be flexed to a selecteddegree, and be rotated about the wire 120 to cut into and disintegratethe thrombotic material of the occlusion. However, when operating theocclusion auger 1000, it is possible that in the case of myocardialinfraction, or MI, deriving from total occlusion, embolic particles maybe released into the distal arterial structure. To prevent such anincident, it is desirable to provide for aspiration of these emboli.Aspiration is possibly achieved via the shaft 130, or by any other ductor lumen allowing fluid communication from an aspiration opening of theduct disposed in vivo at or proximate the distal extremity of theocclusion auger 1000, and leading to an exhaust exit opening of theduct, disposed ex vivo.

FIG. 19B illustrates a suction duct 139 with a suction intake 1391opening adjacent the distal portion of the auger tool 100, appropriatelyconfigured and disposed to discharge any dislocated occlusion debris toan exhaust opening, not shown in FIG. 19B, but disposed ex vivo.

Mechanism of Bending and Expansion

Although described hereinabove, the mechanism governing the two-stepsequence of operation of the auger tool 100, with the bow 110 bendingand expansion process, is now schematically described in further detail,since the successive shapes of bow curvature during the expansion stateare not identical, in reverse, to the successive shapes of bow curvatureduring the bow 110 flexing state.

In a preferred embodiment 1000, illustrated schematically in FIG. 20A,when in the expanded state, the bow 110 is analog to a flat springcantilevered to the shaft 130 at the relief 114 and having the face 112as a free end. To flex the bow 110 into the arcuate state, the shaft 130is distally translated toward the force applicator 122B, which isretained in place by the locked wire 120, disposed against the occlusion320, as by FIG. 20B.

It was described hereinabove that the bow 110 is configured to taper andthat the bow back 117 present a distally diminishing rigidity, thus adecreasing spring rate or spring coefficient, smallest adjacent the face112. Therefore, when the bow is loaded to flex, the “softer” distalextremity bends first, followed by proximal portions of the bow back117, coiling the bow back 117 to gradually roll in atraumatic deflectioninto occlusion tissue.

In FIG. 20B, force is applied on the face 112, shown in FIG. 20A, andthe bow starts to arcuate under the applied bending moment, in gentleand gradual atraumatic rolling motion, into occlusion tissue of thefurrow 340. Simultaneously, the bulb 122B embeds into a tip depression141 and the extrados of the bow 110 embeds in an arc depression 151.

In a further bow curvature deflection phase depicted in FIG. 20C, thebow 110 has further coiled-up and rolled into the occlusion 320,anchoring, the extrados deeper into the occlusion tissue, deepening thearc depression 151, and asymmetrically dilating the vessel 300 radiallyoutward. The bow flexing process ends when the face 112 practicallyabuts the distal extremity of the shaft 130.

When flexed to arcuate as shown in FIG. 20C, the arc depression 151extends distally relative to the tip depression 141. However, the arcdepression may have a span selected from the group of spans consistingof a span extending proximally and distally relative to the tipdepression, a span extending proximally relative to the tip depression,and a span extending distally relative to the tip depression.

The bow 110 is thus appropriately configured with a distally graduallydiminishing spring rate coefficient for deflection under larger force atthe bow root and under smaller force at the face, whereby controlledatraumatic bow deflection curvature is achieved. Therefore, the arcdepression of the extrados is larger and more pronounced than the tipdepression.

In return to the expanded state, and in reference to FIG. 20D, the shaft130 is retained in place while the wire 120 is gradually releaseddistally, relieving the bending moment applied to the bow 110. Theextrados of the bow back 117, which remains embedded in the deepened arcdepression 151, becomes a point of support wherefrom the face 112uncoils distally. The bow 110 now presents an active distal portionspanning from the arc depression 151 to the tip depression 141, incontrast with the flexing state where the span ranged from the relief114 to the tip depression 141. Therefore, the shape of the curvature ofthe expanding bow 110 is different from that of any shape developedduring bending.

The distal portion of the bow back 117 thus gradually uncoils in gentleatraumatic motion to push the force applicator 122 distally into thenewly opened and deepened furrow 340. While the distal portion of thebow 110, extending between the first arc depression 151 and the tipdepression 141 is released to straighten out, the proximal support ofthe bow 110 gradually regresses proximally toward the relief 114, whichis reached upon return to the fully expanded state. This permits theforce applicator 122 of the wire 120 to penetrate distally further intothe furrow 340, as shown in vivo in FIG. 14C.

In addition, the controlled force threshold, step length limit anddeflection curve of the bow 110 provide for control of the radialdilation and forces applied to the occlusion and to the vessel 300.

The mechanism by which the auger tool operates is configured for flexingthe bow back 117 into well controlled deflection curve shapes, and forembedding the tool tip MT first, and thereafter the extrados, to induceatraumatic rolling motion necessary for the radial outward dilation, andfor the distal translation. In other words, the auger tool 100translates substantially axially and distally into the vessel 300 insuccessive crawling motion imparted by each successive sequence ofoperation.

Finally, the mechanism of operation provides for an auger tool 100 voidof free-extending traumatic extremities: The bow back 117 has anextrados extending radially outward and away from the wire 120, but thebow root 115 is retained to the shaft 130, and the face 112 is retainedto the wire 120 by the face bore 113, not only for continuous control ofthe deflection of the bow 110, but whereby there is provided for theforce applicator 122 to be the sole free-extending extremity of theauger tool 100.

Alternative Embodiments

FIGS. 21A to 221C are top elevations of the bow 110 and of the distalextremity of the shaft 130, showing alternative embodiments of theconfiguration and of the method used for retention of the bow root 115to the shaft 130. The bow root 115 is best shaped to fit the functionaldemands required by the manufacturing techniques applied for theretention of the bow 110 to the shaft 130. For example, for fasteningthe bow root 115 by means of rivets 165 to the shaft 130, as shown inFIG. 21A, a rectangular shape 170 for the bow root 115 is well suited,but an hourglass shape 171, shown in FIG. 21C, will suffice. However,the hourglass shape 171 shown in FIG. 21B for retention of the bow root115 to the shaft 130, may provide a better grip for fastening by help ofa shrink tube 116. Nevertheless, other configurations of the shape ofthe bow root 115 may be selected to better suit other fastening meansfor chemical or physical bonding, such as crimping, or any kind ofsoldering, brazing, welding, and diffusion fastening. In fact there isno limit to the choice of shapes for the bow root 115, and for theretention means of the bow root 115 to the shaft 130.

FIGS. 22A and 22B illustrate an alternative embodiment of the bow 110,shown in bottom elevation. Instead of having a planar face, orflat-plane face 112, as seen in FIGS. 2 and 3, the alternativeembodiment has a twisted face 112T presenting a pitch angle. When theexpanded and straightened-out bow 110 is rotated, the face 112T operatesas a segment of a screwthread with a pitch angle to threadingly engageand progress through the occlusion 320.

To further enhance the abilities of the bow 110, with either a planarface 112, or a twisted face 112T, the perimeter 112P of the face may beconfigured as a cutting tool with a plurality of, but with at least onecutting-edge 112C, as shown in FIG. 22B. When rotated, the twisted face112T may chip through the occlusion 320. It is noted that the type offace, either the planar face 112 or the twisted face 112T, does noaffect the controlled bending properties of the bow 110.

As described hereinabove, the proximal retraction of the shaft 130 wasachieved by sliding the face bore 113 of the bow 110, over the wire 120.This retraction method implies that the interior diameter of the facebore 113 must be large enough to permit the passage therethrough of thewidest dimension of the wire 120. In a preferred embodiment, the forceapplicator 122 has a diameter wider than the interior diameter of theface bore 113. However, to penetrate thin vessels 300, it isadvantageous to keep the dimensions of the bow 110, of the face 112, andof the force applicator 122, as small as possible.

To further reduce the dimensions of the auger tool 100, an alternativeauger tool 200 is described hereinbelow, by which, when desired, theshaft 130 may become disengaged from the wire 120 and be retrievedproximally ex vivo, even though the interior diameter of the face bore113 is smaller than the widest dimension of the shalt 130 and of theforce applicator 122.

FIGS. 23A to 23C illustrate a distal portion of the auger tool, asembodiment 200, with a different type of force applicator 122 and face112, and with reduced dimensions. In FIGS. 23A to 23C reference is madeto the planar face 112, but the same applies to the twisted face 112T,with and without one or more cutting-edge(s) 112C.

As shown in FIG. 23A, the force applicator 122 is configured as alimited length of male screwthread 122M disposed at the distal extremityof the wire 120, instead of the bulb 122B shown in FIGS. 2 and 3. Theface 112, shown in FIG. 23B, operates as a female screwthread 113F, ormay be fitted therewith, in replacement of the cylindrical face bore113, to receive the male screwthread 122M therein in matching and inextension therethrough.

To extend the male screwthread 122M distally outward of the face 112, asshown in FIG. 23C, the male screwthread 122M is rotated and threadinglyengaged until distally emerging thereout. Thereafter, once disposeddistally out and away of the face 112, the male screwthread 122M willoperate as a force applicator 122 when the wire 120 urges the face 112.In distal translation of the shaft 130 relative to the static forceapplicator 122M, the male screwthread 122M will apply bending momentforces on the face 112 to arcuate the bow 110. It is noted that the facebore 113, or the female screwthread 113F, have a minimal inside diameterdesignated as w in FIG. 23B, whereas the same dimension w as shown onthe male screw thread 122M in FIG. 23A, is smaller than the maximalexternal diameter of the force applicator 122.

The auger tool 200 having a distal male screwthread 122M, operates inthe same manner as the auger tool 100 with the bulb 122B, to create atip anchoring depression 141 when the bow is flexed to arcuate. However,in the embodiment 200, the male screwthread 122M has reduced dimensionswhen compared to the bulb 112B. For example, the male screwthread 122Mhas a maximal diameter ranging between 1.5 mm and 0.09 mm.

With the auger tool 200, when the operator desires to proximallyretrieve the shaft 130 ex vivo, then the wire 120 is first rotated inscrew thread unfastening rotation until the screwthread 122M is releasedproximally out of the face 112 or the face 112T, as shown when takingthe FIGS. 23A and 23B in mutual relation. Next, the shaft is pulledproximally causing the bow 110 to slightly flex radially outward, toenable sliding over the male screw thread 122M and over the length ofthe wire 120, and its supporting coils.

Another embodiment 600 of the auger tool is described, requiring limitedangular rotation of the wire 120 for release from the face indicated asface 112 but also including face 112T.

Reference is first made to the auger tool 100, to better emphasizedifferences. FIG. 24A shows a circular face bore 113, opened in the face112, when the bow 110 is seen in front elevation. Corresponding theretois the substantially spherical bulb 122B also sown in front elevation,seen in FIG. 24B. In the same manner. FIG. 25A depicts a face 112 withan oval face bore 113OV, and FIG. 25B shows a matching ovaloid forceapplicator 122OV.

It is readily understood that when the main axis of the ovaloid forceapplicator 122OV is appropriately aligned with the main axis of the ovalface bore 113OV, then translation of the wire 120 into and through theface 112 is possible. However, when the main axes of the ovaloid 122OVand of the oval face bore 113OV are out of mutual alignment, say atright angle, as shown in FIG. 25C, then distal extension translation orproximal retrieval translation through the face 122 is prevented. Theoperator OP just has to rotate the wire 120 say by 90° C. relative tothe face 112, to switch from retention of the wire 120 to the face 112,or release there from.

In brief, the force applicator 122 is permanently attached to the distalextremity of the wire 120, and the force applicator 122 and the facebore 113 are configured for either one of both, permitting passage ofthe force applicator through the face bore, and preventing passage ofthe force applicator through the face bore. Likewise, the forceapplicator 122 and the face bore 113 are configured for both, permittingpassage of the force applicator 122 through the face bore 113, andpreventing passage of the force applicator 122 through the face bore113. Thus, the force applicator 122 is retained to the face 112 inproximally controlled attachment release.

If desired, a minute portion 122T of the wire 120 may extend distallyoutward of the force applicator, shown as bulb 122B in FIG. 26, butapplicable to any force applicator 122. The tip portion 122T helps tobetter anchor the force applicator 122 into a tip depression 141 createdin occlusion tissue.

It will be appreciated by persons skilled in the art, that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. For example, the auger tool may have otherconfigurations, as long as atraumatic rolling motion is provided.Furthermore, the auger tool 100, which has at least one flexibleportion, may have more such portions. Likewise, the auger tool 100 mayhave one or more resilient portion(s). Moreover, the auger control forautomatic repetition of the sequences of operation. Rather, the scope ofthe present invention is defined by the appended claims and includesboth combinations and sub-combinations of the various features describedhereinabove as well as variations and modifications thereof which wouldoccur to persons skilled in the art upon reading the foregoingdescription.

1. An occlusion auger for distally traversing, an occlusion in a vesselhaving vessel walls, comprising: a shaft; and an auger tool including aflexible and resilient beam having a proximal end and a distal free end,the distal free end of the beam forming a face, the proximal end of thebeam being fixed to the shaft such that the beam forms a cantileveredbow having a bow back configured as a flat spring, and the bow backhaving a distal taper that provides a lower spring rate at the distalfree end of the beam than at the proximal end of the beam; wherein: theauger tool is configured for atraumatic repeatable operation in asequence including both deflection of the auger tool to an arcuate statein which it extends radially outward, and release of the auger tool fromthe arcuate state to an expanded and straight state, and vice versa, theauger tool having an extrados when arcuate, and a tool tip; the augertool is disposed so as to be adjacent the occlusion; and the auger toolis further configured such that when the auger tool is moved into thearcuate state, the tool tip and the extrados are embedded and releasablyretained in, respectively, a tip depression and an arc depressiondisposed opposite to each other in a spaced-apart relationship in thevessel, such that the vessel is dilated asymmetrically in a radialoutward direction for opening a furrow in the occlusion.
 2. Theocclusion auger according to claim 1, wherein the auger tool isconfigured such that when the auger tool is released from the arcuatestate so as to cause the auger tool to move into the expanded state, thetool tip and the extrados are released from, respectively, the tipdepression and the arc depression, and the tool tip translates into thefurrow distally away from the arc depression, by one step length foreach one sequence of operation.
 3. The occlusion auger according toclaim 2, wherein: the auger tool is configured such that each nextsequence of operation of the auger tool is accompanied by a next distaltip depression, and a next distal arc depression, and both the nextdistal tip depression and the next arc depression are disposed distallyrelative to, respectively, a previous tip depression and a previous arcdepression.
 4. The occlusion auger according to claim 3, wherein: theauger tool is configured for flexing in a controlled deflection curveshape, and embedding the tool tip first, and the extrados is arranged tothereafter induce atraumatic rolling motion for (i) radial outwarddilation, and (ii) distal translation.
 5. The occlusion auger accordingto claim 4, wherein: the auger tool is configured such that elasticenergy accumulated by the bow while flexing when the auger tool is movedinto the arcuate state is liberated to expand the bow when the augertool is released into the expanded state, and the auger tool isconfigured such that operation of the auger tool in a specific number ofsuccessive sequences is accompanied by a same specific number of radialoutward dilations and of distal translations.
 6. The occlusion augeraccording to claim 5, wherein: the auger tool is arranged to translatesubstantially axially and distally into the vessel in successivecrawling motion imparted by each successive sequence of operation, andthe auger tool is configured such that (i) each next sequence ofoperation of the auger tool is accompanied by a next distal tipdepression and a next distal arc depression, and (ii) both the nextdistal dip depression and the next are depression are disposed distallyrelative to, respectively, a previous tip depression and a previous arcdepression.
 7. The occlusion auger according to claim 1, wherein: theshaft has an ex vivo proximal end, an in vivo distal end, an exterior,and an interior supporting therein a wire having an ex vivo proximalextremity portion and an in vivo distal extremity portion, the bow ofthe auger tool is disposed in distal coextensive longitudinal alignmentwith the distal end of the shaft, the bow back of the bow isintermediate a bow root fixedly attached to and supported by the distalend of the shaft, the face formed at the distal free end of the bowextends distally away from the bow back, the face having a face borewhich is configured for passage therethrough of the wire, and a forceapplicator is retained at the distal extremity of the wire andconfigured for operative association with the face bore and with theshaft, to (i) flex the bow to the arcuate state when the shaft istranslated distally relative to the force applicator, for the extradosto dilate the vessel asymmetrically in the radial outward direction, and(ii) release the bow to the expanded state when the wire is released,for the face to translate the force applicator distally away relative tothe arc depression by one predetermined step length for each onesequence of operation.
 8. The occlusion auger according to claim 7,wherein: the bow has at least one flexible element.
 9. The occlusionauger according to claim 7, wherein: the bow has at least one resilientelement.
 10. The occlusion auger according to claim 7, wherein: theforce applicator is disposed in longitudinal coextensive distalalignment with the face, and the bow is tangential to and longitudinallyaligned with the shaft, and is configured to taper from the bow rootdistally away to reduce dimensions, thereby forming a single protrusionextending radially outward relative to the wire, whereby alignment ofthe force applicator with the face, tapering of the bow, and the singleradial protrusion enhance reduced dimensions.
 11. The occlusion augeraccording to claim 7, wherein: the force applicator is permanentlyattached to the distal extremity of the wire, and the force applicatorand the face bore are configured for one of (i) permitting passage ofthe force applicator through the face bore, and (ii) preventing passageof the force applicator through the face bore.
 12. The occlusion augeraccording to claim 7, wherein: the force applicator and the face boreare configured for both permitting passage of the force applicatorthrough the face bore, and preventing passage of the force applicatorthrough the face bore.
 13. The occlusion auger according to claim 7,wherein: the force applicator is retained to the face in a proximallycontrolled attachment release.
 14. The occlusion auger according toclaim 7, wherein: the bow is tapered to reduce dimensions, the bow isconfigured with a distally gradually diminishing spring rate coefficientfor deflection under larger force at the bow root and under less forceat the face, and the auger tool is configured such that the arcdepression of the extrados is larger than the tip depression.
 15. Theocclusion auger according to claim 7, wherein: an auger control isdisposed ex vivo in operative association with the auger tool, the augercontrol comprising: a common axial conduit configured to accommodatebi-directional translation therethrough and bi-directional rotation ofthe wire, the wire being retrievable distally and proximally, wherein adistal portion of the conduit is configured to accommodatebi-directional displacement in translation and in rotation of the shaft,the shaft being retrievable distally; two force limiters, including awire force limiter operatively coupled to the wire and a shaft forcelimiter operatively coupled to the shaft, configured for adjustableselection and setting of a predetermined threshold limit of forcesapplied to the auger tool; and a step limiter configured for adjustableselection and setting of a predetermined distal step length taken ineach one sequence of operation, wherein the wire, the shaft and the twoforce limiters are operative independently and in combination.
 16. Theocclusion auger according to claim 15, wherein: the auger control isarranged to maintain identical predetermined forces limit and steplength settings for each sequence in a series of successively repeatedsequences.
 17. The occlusion auger according to claim 15, wherein theauger control further comprises: a shaft lock for releasably locking theshaft relative to the auger control and for limiting force applied onthe shaft, a stepper for distally translating the shaft in predeterminedstep length; and a wire lock for releasably locking the wire relative tothe auger control and for limiting force applied on the wire; andwherein the auger control is configured for operative handling andcontrol of the wire and of the shaft both independently and incombination.
 18. The occlusion auger according to claim 7, wherein theauger tool is configured such that when the auger tool is in the arcuatestate: the bow back has the extrados and the extrados extends radiallyoutward and away from the wire, and the bow root is retained to theshaft and the face is twisted to present a pitch angle and is retainedto the wire by the face bore, for continuous control of the deflectionof the bow, whereby the force applicator is the sole free-extendingextremity of the auger tool.
 19. The occlusion auger according to claim7, wherein: at least one cutting edge is disposed on a perimeter of theface to extend radially outward and away from the face bore, and the atleast one cutting edge is configured for radially cutting into occlusiontissue, by operating in vivo as a segment of a screwthread with a pitchangle to threadingly engage and progress through the occlusion.
 20. Theocclusion auger according to claim 7, wherein: (a) the force applicatoris adapted to be navigated to engage an axial furrow in an occlusion,(b) the face is adapted to be abutted on the force applicator, (c) theauger tool is adapted to be operated to the arcuate state of the bow togather energy, whereby kinetic energy is accumulated and the bowasymmetrically dilates the vessel into one radial outward direction, (d)the auger tool is configured such that the energy gathered in thearcuate bow of the auger tool is released to the expanded state, and thereleased kinetic energy extends the bow to translate the forceapplicator distally into the furrow.
 21. The occlusion auger accordingto claim
 7. wherein the auger tool is configured such that in thearcuate state of the auger tool: the force applicator is adapted toreleasably embed in a tip depression, and the extrados is adapted toembed in an arc depression to dilate the furrow, and to initiate a crackpropagation mechanism to open and distally deepen the furrow, andwherein the auger tool is configured such that in the expanded state ofthe auger tool: the force applicator is adapted to be received by onestep length distally deeper in the deepened furrow.
 22. The occlusionauger according to claim
 17. wherein the occlusion auger is configuredsuch that when the force applicator extends distally past an occlusion,one of (i) the wire is adapted to be navigated to engage a nextocclusion and a next occlusion traversing sequence is performed, and(ii) the shaft is adapted to be proximally retrieved ex vivo while thewire remains disposed in place for use in a next treatment intervention.23. The occlusion auger according to claim 17, wherein the occlusionauger is configured such that when the force applicator extends distallypast a traversed occlusion, the shaft is retrievable ex vivo, by one of(i) retrieving the face bore proximally away relative to the forceapplicator and sliding the face bore over the wire, and (ii) disengagingthe face distally away from the force applicator, and retrieving theshaft proximally.
 24. The occlusion auger according to claim 7, wherein:the step length ranges from 1 mm to 50 mm.
 25. The occlusion augeraccording to claim 7, wherein the auger tool is configured such that:the tip depression is disposed opposite the arc depression, and the arcdepression has a span selected from a group of spans consisting of aspan extending proximally and distally relative to the tip depression, aspan extending proximally relative to the tip depression, and a spanextending distally relative to the tip depression.
 26. The occlusionauger according to claim 1, wherein the proximal end of the beam isfixed to the shaft such that a portion of the beam extends alongside theshaft.
 27. The occlusion auger according to claim 1, wherein theproximal end of the beam is fixed to the shaft such that relative motionbetween the beam and the shaft is prevented.
 28. The occlusion augeraccording to claim 1, further comprising a wire extending through theshaft and through a face bore in the face at the distal free end of thebeam, the beam being fixed to the shaft such that a portion of the beamextends alongside a portion of the shaft through which the wire extends.